This invention relates to generating gas atmospheres.
Endothermic gas atmospheres (i.e. atmospheres prepared using the addition of heat) are typically prepared in an endothermic gas generator (e.g., a class AGA 302 generator) by reacting a rich mixture of air and combustible hydrocarbon gas inside an externally heated reactor (called a retort) in the presence of a catalyst, e.g., nickel. These atmospheres are useful as furnace atmospheres for the performance of various metallurgical processes, e.g., carburizing, carbonitriding, and clean hardening. The composition of the atmosphere affects the performance of the metallurgical process. Thus, it is important to maintain the predetermined composition of the endothermic gas atmosphere throughout production.